The use of a semi-tractor with a farm trailer would have advantages over a conventional farm truck. A semi-tractor is not limited to a single trailer but can be used with a variety of different trailers. Repairs and maintenance of the tractor can be made without tying up the trailer.
Many gravity dump trailers are available. However, many uses for farm trucks or trailers require hydraulic end dumping rather than gravity dumping. What the step frame trailer provides is a trailer designed to be fitted with an end dumping standard grain or silage box and a standard hydraulic lift hoist. The height of the semi-tractor fifth wheel plate determines the height of the trailer frame. Thus, what is needed is a way by which a grain or silage box can be kept as low as possible for ease of loading and unloading and for stability and yet be connected to a fifth wheel plate on a semi-tractor without modification of the box.